Electric heater



Oct 9, 1928. 1,686,868 H. G. LANDIS ELECTRIC HEATER Filed Nov. 2, 1

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J7 J7 J1 10 15 W. 2 13 6 INVEN TOR Ha h GLandis BY mm ATTORNEY Patented Oct. 9, 1928.

UNITED STATES HUGH GRAHAM LANDIS, 01 SAN FRANCISCO, CALIFORNIA.

ELECTRIC ima'rna.

Application filed November 2, 1925. Serial No. 66,212.

This invention relates to improvements in electric room heaters of the small unitary type, one of the objects of my invention being to provide a heater so constructed that i a strata of heated air moving at considerable velocity is established, which separates the heated from the unheated volumes of air and results in very high efficiency of heat production.

Another object is to arrange for the cold air to be drawn upwardly from the floor or from below the level of the heatingelements, subjecting such air to the electrical heating influences, and then discharging the air horizontally toward the walls of the room. A continuous and forceful circulation of air is therefore set up which prevents the heated air from rising to and staying at the top of the room or near the ceiling as is usually the case with heating devices. sures that all air in the room will sooner or later be heated and then reheated until the thermostatic control causes the discontinue: tion of operation of the heater.

The device is preferably arranged in portable form so that it may be shifted around from one place to another as may be found desirable by the user. It is also of such simple and compact nature, however, that it may be incorporated in connection with an electric light fixture suspended from the ceiling, to the stems of piano lamps, to the pedestals of dining room and similar tables; or arranged with other articles of furniture.

A further object of the inventionis to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of ref erence indicate corresponding parts in the several views:

Fig. 1 is a sectional elevation of the apparatus arranged as a portable unit, with the motor idle.

Fig. 2 is a similar view of the operating mechanism detached with the motor in operation.

Referring now more particularly to the characters of reference on the drawing, the numeral 1 denotes a small electric motor dis- This also inposed with its shaft in a vertical plane. The motor is supported on a pad or base 2 preferably of rubber to absorb vibration and noise. This base extends around the motor and is supported by a housing which in the present instance is shown in the form of a vertical cabinet 3 of neat character, arranged to maintain the motor a certain distance from the floor. The cabinet may be made in different designs, corresponding to difi'erent furniture designs so as to harmonize with the room in which it may be placed.

The base 2 is provided with a number of orifices 4 located between the motor and the sides of the cabinet and a dust screen 5 is removably secured to the base below the same and extends across all the orifices and the motor.

Mounted on the motor shaft and projecting above the motor is a spindle 6 on top of which is mounted a solid circular plate 7. This plate has depending therefrom adjacent its periphery, a number of vanes 8 shaped to form a multivane centrifugal fan to blow air horizontally from under the plate 7. The vanes extend nearly to the sides of the cabinet or housing, which in the vertical plane of the vanes is provided with any suitable number of openings 9. Except for these openings however the cabinet is closed from the top to the under surface of the base 2. As shown in the drawings the top of the cabinet is comprised of the top plate 20 spaced from the circular plate 7. This forms an intermediate dead air space 21 which insulates the top plate 20 so that heat from the elements does not affect same. Thus ornaments or flowers or potted plants may be supported on the said plate 20 without being materially affected by the heat from the elements.

Fixed on the spindle 6 and projecting upwardly therefrom to a termination 11. short distance below the plate 7 is afunnel shaped receptacle 10 in which a certain amount of mercury 11 is carried. The top of the repeptacle has a horizontal inturned flange or Blhe upper edge of the receptacle terminates a. sufficient distance from the inner edges of the vanes 8 to allow of the lacing of a number of verticall disposed eatin coils, mounted in spaced relation to eac other and to the receptacle and vanes. Two

horizontally inwardly of said opposed ones of such coils are illustrated at 13 and they are supported by suitable pads 14 projecting inwardly from the housing.

One lead 15 extends from a convenience outlet 16 or other suitable terminal means on the side of the. housing to one coil, while the other lead 15 extends to the other coil. A contact strip 17 extends from each coil over the flange 12 and is then bent under and flange, these strips being maintained in spaced relation to thereceptacle and to each other, The leads 18 from the motor, on a separate circuit, extend to a convenience outlet 19 or' the like'on the side of the housing. The two outlets 16 and 19 have, for the sake of clearness of illustration, been shown as being on opposite sides of the cabinet, but in practice they could of course be alongside each other or concealed inwardly of the cabinet below the base 2 if desired.

The motor is of very small horse power and is connected to the ordinary light circuit. A simple form of thermostat controlled by the heat of the room can therefor-e be used to control the opening and closing of the motor circuit.

For the sake of heating efficiency however I contemplate using heating coils of such capacity that heavier house wiring, such as is used in connection with electric stoves, would be necessary, This necessitates a separate circuit for the heating coils and would re uire a different form of thermostat switch, if such were used, to control such circuit.

The strips 17 together with the receptacle 10 and the mercury therein provide however a simple and positively operating form of switch for the heating coils, so that a thermostat in the-motor circuit is the only one necessary.

\Vhen the motor is idle as in Fig. 1 the mercury of course rests in the bottom of. the receptacle. WVhen the motor circuit is closed and the motor attains a certain speed the mercury is thrown centrifugally in the receptacle, and owing to the shape of the latter, rises until it reaches the flange 12. The mercury is confined by such flange and fills the pockets formed by the flange and the side wall of the receptacle as shown in Fig. 2. This confined mercury is then of course in the form of a continuous .ring and engages the strips 17. The circuit to the coils is then closed, causing the coils to be heated; and the circuitwill remain closed until the speed of the motor drops to a considerable degree for lack of sufiicient current in the lineor when the heat attained in the room causes the theremostat to open the motor circuit.

WVhen the motor is thus operating the fan of course is turning also inducing a tendency to vacuum in the housing above the base 2.

This causes air to be drawn upwardly throng-i the orifices 4 from adjacent the floor or-the room, and such air is discharged through the openings 9 in the housing by the action of the fan vanes. p Before passing through these openings however the air must pass by the heatin coils and is subjected to the heat thereo causing the air when distributed to be in a heated condition. 7 When the coils have been heated for a short time their heat is of course imparted to the vanes and receptacles 10 as well, so thatadditional heating surface with which the air contacts is provided.

. The shape of the receptacle 10 not only causes the mercury to move up and function as a switch but also forms a deflector for the air, eliminating blind pockets in the housing and deflecting the air as it is drawn up toward the coils and fan vanes.

A constant stream of relatively cool air passing over the heating elements, these members are prevented from attaining such an intense heat as would cause them to soon burn out,

The elements will therefore last much. longer than is the case with the elements of an ordinary heater.

Though I have designated theheater as being small, this termapplies to its size alone, since its h'eatin capacit is very great for its size, and is far' laeyond t wt of an ordina il'y heater of equal bulk.

he construction and arrangement of parts-herein described is, I believe, the best for the most efiicient results. However different forms of fan, elements, and a diflerent arrangement of these parts in the housing may obviously be employed if found desirable without departing from the spirit of the invention. I

Other forms of automatic or centrifugalaction switches may also be used in place of themercury switch shown. I

From the foregoing description it will be rcadilyseen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein;

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

1. An electric room heater comprising a motor driven fan, heating elements arranged in the path of air currents induced by e fan, separate circuits for the motor and heating elements, and a switch means for the elements circuit including a vertically disposed receptacle arranged in connection with the motor to be rotated thereby, separated contactmembers in the element circuit overhanging and depending into the receptacle, and a current conducting liquid in the receptacle of a quantity insufficient to engage the contacts when the receptacle is idle;

the latter being so shaped that with the rotation thereof said liquid will be thrown centrifugally and upwardly to form an endless ring constantly engaging the contacts.

2. An electric room heater comprising a motor driven fan, heating elements arranged in the path of air currents induced by the fan, separate circuits for the motor and heating elements, and a switch means for the elements circuit including a vertically disposed receptacle arranged in connection with the motor to be rotated thereby, said receptacle being of inverted cone shaped form, an inturned flange around the rim of the receptacle, spaced contact strips connected in the element circuit and projecting under the flange, a current conducting liquid in the receptacle, said liquid being insufficient in quantity to engage the contacts when the receptacle is idle.

3. An electric heater comprising a motor, a driven spindle projecting upwardly therefrom, a horizontal plate on top of the spindle, vanes depending from the plate adjacent the periphery thereof to form a multivane centrifugal fan; vertical heating coils arranged inwardly of the vanes under the plate, a housing surrounding the fan and having lateral openings in the vertical plane of the vanes, and a horizontal support in the housing for the motor disposed below the fan and coils, said support being in spaced relation to the floor and having openings to allow air to pass upwardly to the coils and fan.

4. An electric heater comprising a motor, a driven s indle projecting upwardly therefrom, a orizontal plate on top of the spindle, vanes depending from the plate adjacent the periphery thereof to form a, multivane centrifugal fan; Vertical heating coils arranged inwardly of the vanes under,

the plate, a housing surrounding the fan and having lateral openings in the vertical plane of the vanes, a horizontal support in the housing for the motor disposed below the fan and coils, said support being in spaced relation to the floor and having openings to allow air to pass upwardly to the coils and fan, and a circular deflector plate concentric with the motor and above the same, said plate flaring outwardly from its lower end and terminating adjacent the under face of the horizontal plate inwardly of the coils.

5. An electric room heater comprising an electric motor, a fan driven thereby, heating elements arranged inwardly of the fan, separate circuits for the motor and heating elements, spaced contact strips interposed in the element circuit, and movable means for engaging and bridging such strips; said means being actuated by the centrifugal force set up with the eration of the motor to then engage said strips.

6. An electric heater comprising a vertically disposed motor, a driven spindle projecting upwardly therefrom, a horizontal plate supported b the spindle at the top, vanes dependin rom the plate to form a multivane centrifugal fan, electric heating elements arranged under the plate inwardly of the vanes, and a continuous deflector member extending upwardly and outwardly about the spindle and under the plate, and inwardly of the elements.

7. An electric heater comprising a stand having a substantiall flat top, the heating means bein dispose below the plane of the top of t e stand, such top being hollow to form aninsulating dead-air space between the heating means and the top surface of the stand whereby objects placed on the stand will not be materially affected by the heat from the heating means.

8. An electric heater comprising a vertically disposed base housing freely open diametrically from end to end, means supporting the lower freely open end of the housing above the ground level to permit a substantially uninterrupted flow of air from all points of the compass around such housing radially to the edge of the open lower end thereof and hence into the housing, a horizontal and imperforate top supported upwardly from the top of the housin to provide an open slot between the two an all around the heater, a driven fan between the slot and the lower open end of the housing arranged to cause air to be drawn from the circumferential area all around the housing radiall to the edge of the'lower open end thereo and thence through the housing and to discharge it in stratra-like formation through the slot, and a heater interposed in the line of travel of the air.

In testimony whereof I afiix my signature.

HUGH G. LAN DIS. 

